Internal-combustion engine.



P. G. TACGHI. INTERNAL eoMBUsTIoN ENGINE.

APPLICATION FILED MAR. 3, 19.13. 1,1 12,338, Patented Sept. 29, 1914.

3 SHEETS-SHEET 1.

nouvo P. G. TAGCHI.

INTERNAL GOMBUSTION ENGINE. APPLlcATloN FILED MAKS, 191s.

1,1 1 2,388, f Patented Sept. 29, 1914.

3 SHEETS-SHEET 2.

P. G. TACCHI.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAR. a, 1913.

1,1 12,338, Patented Sepb.29, 1914.

' HEBT 3.

5 3 SHEETS S PERCY GEOGE 'IACCHLAOIF ACTION, ONDON, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Sept. 29, 1914.l

Application led March 3, 1913. Serial No. 751,884.

To all whom, t may concern.'

Be it known that I, PERCY GEORGE TACCHI, residing at 29 N emoure road@Acton, London, in the county. of Middlesex, England, engineer', haveinvented a newk and useful Improvement in or Relating to Internal-Combustion Engines, of which the followmg is a specification.

This invention vrelates to internal combustio-n engines having cylindersarranged radially with or tangentially to a central shaft to which theyare attached and with which they revolve.

In the specification to my application No. 709,525 is described anengine of the above type, which is characterized by each piston beingprovided with a roller mounted on a gudgeon pin and bearing against theinner surface of a ring fixed in the plane of the cylinders buteccentric to the shaft with which they revolve, the stroke of eachpiston corresponding with the eccentricity of the said ring rIhe ringintersects the cylinders at the outer ends of the latter, and thepistons may also be slotted at their outer ends to receive the ringsothat they are prevented from turning in their cylinders. This engineworks on a two-stroke cycle, and the primary object of my presentinvention is to provide an engine of a similar type capable of workingon a four-stroke cycle. With this object, I construct each piston withan enlarged base or outer end, the annular surface of which is equal inarea to the top or inner end of the piston, and I causethe ignition ofthe combustible mixture to-take place at the inner and the outer ends ofthe piston alternately. ,'Ihat is tos'ay, during the expansion of theproducts of combustion in the inner end of the cylinder a charge ofcombustible mixture is being drawn into the outerY end ofthe cylinder,this charge is then compressed during the return stroke while the wastegases from the previous charge in` the inner end ofthe cylinder arebeing expelled, ignition of the charge in the outer end of the cylinderis, now effected and duringthis working stroke of the piston a freshcharge is being drawninto the inner end of the cylinder, anchnally onthe fourth stroke of the piston the fresh charge in the inner end of thecylinder is compressed while the waste gases are being expelled from theouter end of the cylinder.

An engine embodying my present' invention is illustrated intheaccompanying drawings, in which Figure 1 is afragmentary side view ofthe engine partly in section and partly in elevation, and Fig. 2 atransverse section. Fig. 3 illustrates in side elevation and to anenlarged scale the cam for operating the inlet and the exhaust valvesand Fig. 4 is a seotion on the line m--m in Fig. 3 and shows the shapeof lthe ca'm. Fig. 5 illustrates diagrammaticallya modificationhereinafter described. Fig. 6 is a side elevation of the cam employedwith the modified construction, and Fig. 7 is a section through the camgroove and shows the shape of the cam. y

In the construction illustrated the engine comprises four cylinders, butthe number of cylinders may be increased if desired or decreased tothree cylinders. Each cylinder, for a yportion of its lengthcorresponding to the stroke of the piston, is larger in diameter at itsouter end a than at its inner end b, and at the junction of these twodiameters are oppositely disposed inlet and outlet openings a, a2, whileat the extremity of the inner end are similar openings b, b2. Within thecylinder is a piston having an -enlarged end a3 corresponding to thelarger diameter a of the cylinder, and a smaller end b corresponding tothe smaller diameter b' of the cylinder. The ^annular face a4 of thelarger end of the piston should equal in area the face b4 of4 thesmaller end thereof, so that the forces acting at each end of the pistonmay be equal. The v'larger end a3 of the piston is furnished with aroller c which may be mounted upon a gudgeon pin c in the mannerdescribed in'rny aforesaid specification, but in order to minimizefriction I prefer to support theroller c upon roller bearings 02 mountedupon the gudgeon pin c, while the ends of the latter are supported inroller bearings c3 mounted in the wallof the piston. The roller o bearsagainst the inner face of a ring d which is fixed to the casing e and iseccentric to the shaft f. In the present application the ring or track dis not shown merely as a true circle eccentrioally disposed relativelyto the shaft as in my aforesaid application, but as an alternative Fig.l shows a ring having its radius fromthe shaft f gradually increasing`through an angle of about 120, then continuing this vincreased radiusunaltered from 120o to 240 and for the remainder of the circle the raldius is gradually reduced to meet the minimum-radius at 360. The gradualdecrease 'in the radius of thering may, however,

commence from 120o ii' desired and be continued'to 360?. The ring d isin the plane of the cylinders, and the outer ends a of the latter areslotted at d to clear the said ring;

the pistons outward when t e engine is re volved for starting. v

The inlet openings a', b', in each cylinder for thecad'mission of fuelare connected together by means of a conduit g, and the outlets a?, b2.for the `waste -gases are similarly connected together byk means of aconduit 71,. The discharge of the waste gases from the outer end a andthe inner end b of each cylinder is controlled respectively by valves L,11,2, which are mounted in said conduit l1. and have their spindlesextending toward the shaft f. 'Concentric with this shaft and oppositethe spindles ofthe valves is a cam z' which is fixed by means of theflange z" to the casing e of the engine. The cam consists of two grooves112, 3, which are parallel for a portion of their lengths and then crosseach other, as shown in Figs. 2 and 3.' Fig. 4 shows lone of the groovesin section and illustrates the contour of the cam. These grooves receivea tappet j which is connected to the cylinder in any suitable manner,as, for example, by means of a link if attached by a ball-and-socketjoint jz to an arm j3 extendingfroin-the cylinder; a spring j? beingprovidedto maintain the tappet in engagement with the cam. During therotation 'of the cylinder in the direction of the arrow shown in Fig. l,the tappet y' travels along the oblique portion of one of the grooves(say 712)' and across from the spindle of one of the valves (Say L) tothe spindle of the other valve, when it enters the other groove (i3),and opens the second valve (71,2) by reason of the larger or annularportion of the cam groove forcing the tappet y' outward against thevalve spindle. In a similar manner, the tappet j after operating thevalve h2 passes from the groove is to the groove 2 and operates thevalve 71.. These two valves are thus alternately opened during eachsecond out stroke of the piston, so that at each second instroke firstthe outer or enlarged end a3 of the piston expels the waste gases fromthe larger end @of the cylinder, and then at the following instroke theinner or smaller end b 4expels the waste gases from the smaller end b ofthe cylinder. These gases enter the conduit it whence they pass by wayofan opening h3, into a channel e formed in the casing e and thenceescape. The channel e is in the form of an arc corresponding to theangle through which the cylinder passes during the discharge of thewaste gases, and in the example illustrated in Fig. 1 the angle is 240,extending from to y. The channel e is closed by a ring h4 which bearsagainst a floating ring h and in which ring are formed the outlets k3from the conduits 7L.

The admission of the combustible mixture into each cylinder. iscontrolled by means similarlto those above described for controlling thedischarge of the waste gases. Each conduit g is provided with valves g,g2, which respectively control 'the inlets a', and which are operatedalternately yby a tappet j working in a cam 0 similar to the cam z', thefuel inlet valves being operated in a similar manner to the eductionvalves. The conduits g communicate with a channel c2 which is similar tothe channel e', but oppositely disposed and which receives the fuel fromthe source of supply and conveys it to the conduits of the severalcylinders. The fuel may, however, be su plied to the conduit g by way ofthe sha t f which for this 95 purpose would be made hollow. In theconstruction illustrated, the water for cooling the cylinders isconveyed through a tube f in the axis of the shaft, whence it passes, byWay of passages f4, to a jacket formed between two disks f, f, inclosingthe cylinders, and after circulating about the cylinders escapes by Wayof the annular passage f formed around the tube f3. In Fig. 2 the inletand outlet for the water are shown on the fuel supply side of thecylinders, but it will be obvious that the tube f8 may he on theopposite side for supplying the Water, and that the fuel may be suppliedthrough the axis of the shaft on the fuel side of thc cylinder. l

The sparking plugs .76, Z, are mounted in the exhaust conduits a2, b2,but they may, if desired, be mounted in the fuel conduits a,

b and respectively collect current from opposits sides of a ber ring 7cmounted upon the case e and each furnished with contact segments withwhich wipers 7a2, Z2 make contact as the cylinders revolve.

For lubricating the engine the casing e is supplied with oil into whichthe pistons dip when at the outer ends of their stroke, and the rollersc throw the oil to the inner ends of the pistons where it exudes throughperforations m and lubricates the inner end of the cylinder. To retainla supply of oil within the smaller end o of the piston a gutter m2 isprovided adjacent to the perforations.

In the Working of the engine, each cylinder while revolving operatesasfollowsz- Referring to Fig. 1 and assuming a charge of fuel to becompressed in the enlarged end u of the cylinder 1, ignition of thischarge is effected and the expansion of the products of combustion takesplace while the cylinder is traveling through an angle of 120. Duringthis period the piston in the cylinder moves the full length of itsoutward stroke and its smaller end draws a charge of fuel into theportion Z) of the cylinder, the inlet valve g2 of which has meanwhilebeen opened by its tappet j and cam i". At the end of thisperiod theoutlet valve t is opened and the waste gases escape from the n end awhile the cylinder is traveling through the next angle of 120; thepiston during this period remaining stationary in its cylinder. Thecylinder having now traveled through an angle of 240 the fuel inletvalve g2 of the portion Z1 is then closed but the outlet valve L of theportion a is maintained open to permit the expulsion of the waste gasesfrom the cylinder while traveling through the remainder of itsrevolution at the end of which the valve L is closed. During this thirdperiod of 120 the piston is forced inward and compresses the charge offuel in the portion of the cylinder. At the second revolution of theengine the above cycle of operations is repeated but reversed in theopposite ends. of the cylinder. That is to say, while expansion of theproducts of combustion is taking place in the smaller end b ofthecylinder fuel is being drawny into the larger end a thereof, then Whilewaste gases are escaping from the smaller end b of the cylinder fuel isbeing admitted into the larger end a thereof, and, finally, while thewaste lgases are being expelled from the smaller end b of the cylinderthe fresh charge of fuel is being compressed in the larger end athereof. It is not, however, essential that the piston should remainstationary in its cylinder for a period, as its inward travel may becommenced immediately after the end ofits out stroke; and it will beobvious that this may be effected by commencing the reduction of theradius o-f the cam ring at 120 the piston then moving inward duringtwo-thirds of a revolution of the engine and outward during onethird.

According to an alternative mode of construction the four strokes of thepiston of each cylinder may be effected during one revolution instead ofin two revolutions of the engine. This is accomplished by constructingthe ring d approximately elliptical in form, as shown diagrammaticallyin Fig. 5, while the valves are operated by cams of the constructionshown in'Figs. 6 and 7. Referring to Fig. 5, and assuming each cylinderto be rotating in the direction of the arrow, vthe working of the engineis as follows :-ln the first quadrantv expansion of the products ofcombustion takes'place in the enlarged portion a. of the cylinder Whilefuel is admitted into the smaller end b. Seco-nd quadrant, dischargev ofthe waste gases from portion a and compression of fuel in portion 5 ofthe cylinder. Third quadrant, admission o-f fuel into portion a of thecylinder and expansion of products of combustion iri portion b. Fourthquadrant, compression of fuel in portion a of the cylinder and expulsionof waste gases from portion b of the cylinder. To enable the eductionvalves of the outer andV inner ends of the cylinders to be openedalternately while the cylinder is traveling through the second andfourth quadrants, the tappet for these valves work in a cam groove ofthe form shown in Fig. 6 and comprising a channel a in the plane o-f theouter eduction valve, and a channel n in the plane of the inner eductionvalve. These two channels are in opposite quadrants and are of thecontour shown in Fig. 7, while two channels n2, fn, connect the channelstogether so that the tappet may pass from the one to the otheralternately. J

What I claim as my invention and desire to secure by Letters Patentis- 1. Inan internal combustion rotary engine, the combination of arotatably mounted shaft; a plurality of radiating cylinders aiixedthereto, each cylinder having a pair of piston chambers of differentdiameters; a correspondingly shaped reciprocating piston operating ineach of said cylinders and having a pair of Working faces; inlet andexhaust ports for said piston chambers; ignition mea and an annularlyshaped track having an uninterrupted tread surface movably engaged bysaid pistons, a portion of said track having al curvature graduallyincreasing in radius, a contiguous portion remaining unaltered at themaximum length of said increased radius, and the` curvature of theremaining portion being gradually reduced in radius/to meet the minimumradius.

2. In an internal combustion rotary engine, the combination of arotatably mounted shaft; a plurality of radiating cylinders aiixedthereto, each cylinder having a pair of piston chambers of differentdiameters; a correspondingly shaped piston operating in each of saidcylinders and having a pair of working faces; ignition means; inlet andexhaust orts for said piston chambers; valves contro ling said vinletand exhaust ports having spindles extending into proximity with saidshaft; a pair of stationary annular cams mounted on said shaft adjacentsaid valvel spindles, each provided on its annular peripheral surfacewith a pair of eccentric cam grooves, said cam grooves being annu-`larly disposed and arranged parallel for a rgage said cam grooves foralternately portion of their circumference, thence crossing each otherto meet its complementary cam groove; spring controlled-tappets havivchambers of diiierent diameters; a corre. jspondingly shapedreciprocating piston operating in each yof said cylinders and having apair of Working faces; a cam-shaped track,

having an uninterrupted tread surfaceencircling and movably engaged bysaid pistons; an arc-shaped channel formed on each side of said casing;an inlet conduit for each cylinder, communicating with said pistonchambers, and havin an opening register-4 ing with one of sai arc-shapedchannelsj an exhaust conduit for eachof said c linders communicatingwith said piston c ambers and having an opening registering with saidother arc-shaped channel; ignition means;

and automatically 'operated valves controlling said inlet and exhaustports.

` In' Witness whereof I have hereunto set my hand in the presence of tvvo witnesses.

rERoY GEORGE TAoeHr.

Witnesses:

E. L. H. EL'LIo'rr, I. H. BoYLE.

